Bishop Hill The ancient history of the Hockey Stick
Sep 11, 2013 Climate: MWP Bernie Lewin is in the blogging saddle again and has written a fascinating account of the early history of the millennial temperature reconstructions.
There is one temperature reconstruction of the last millennium that skeptics love to hate. And there is another that skeptics idolize in its place. The one is the ‘Hockey Stick’ northern hemisphere reconstruction, while the other appears as a schematic global trend line in the First Assessment Report of the IPCC. But neither graph is any good. They both obscure and distort the underlying science. Moreover, the skeptic’s idol itself usurped yet another dubious graph that reigned through the late 1970s and early 1980s. Thus, since global climate change anxiety emerged in the 1970s, we find a succession of three iconic millennium temperature graphs, each as different from the other as they are obscure in their scientific grounding. What is strange is that such plastic transformations are not found with the conventional reconstructions at smaller and larger timescales. The trend on the geological scale was only being refined over the same period. The large scale 100-year trend line has been more controversial. But both have maintained their general characteristics throughout the cooling and then warming alarm. So, what is it about the 1000-year timeframe? In the next couple of posts we uncover the origins of the two predecessors to the Hockey Stick. While the earliest version is as obscure in its origins as it is forgotten today (Part II not yet posted), the other remains the idol of the skeptic (Part I). And so smash it we do!
I'm not sure that the Lamb hockey stick is idolised as such, but this probing into the early history of the paleoclimate scene looks as though it will be pretty interesting. Read the whole thing.
Reader Comments (17)
I don't think that the Lamb/MWP graph is an "idol" for skeptics.... More like a point of comparison for discussion of how IPCC science went from an assertion of a very substantial MWP to a bogus Mannian hockey stick with no adequate data analysis.
What had seemed obvious enough to many climate scientists to be included in CliSci reports into the 1990s suddenly was discarded in favor of the strange statistical sausage-making of Mann et al.
Obviously the Lamb graph does not display any precise data calibration -- it looks like someone's conceptual estimates, sans exact data. But the quest for scientific precision does not properly include the Mannomatic made-up statistics....
I do not think anyone has ever said "let's take no action" using Lamb's graph as the reason.
This is an obscure backwater of science that has been given leverage far beyond its confidence and scientific techniques.
However, the difference is that perhaps Lamb did his without deciding what the result was required to be.
The author repeatedly uses the word "obscure", shouldn't that be a giveaway? Later HS reconstructions could never be described as "obscure".
Idolised? He is just building up professional ego as the HS slayer.
It's a really unfortunate setup, I agree with Andrew, Skip and JC. Nobody has ever idolised Lamb's useful sketch. What I think has been present is nostalgia for the more innocent days it represents. Or indeed an emotion stronger than that. But we never confused lost innocence with dumb belief in an unimpeachable accuracy of the sketch its author himself would not have claimed. Nor were we fooled by the sequel.
There have been many published data examples exhibiting a medieval warm period and they cover most parts of the globe, so I do not agree with the suggestion that it was restricted to Europe. It may be true that these datasets have not been merged, which is perhaps a fair point.
However, the author seems to have overlooked Criag Loehle's paper from 2007:
Loehle, C. 2007. A 2000 Year Global Temperature Reconstruction based on Non-Treering Proxy Data. Energy & Environment 18:1049-1058.
Loehle's work when published was unique because it:
(a) is a global reconstuction
(b) uses no tree rings
(c) only uses proxies that had already been peer reviewed and published.
It clearly shows a substantial medieval warm period and looks remarkably like the graph in the original IPCC report.
a paper that might be of interest to some:
D Frank, D., J. Esper, E. Zorita, R. Wilson. 2010. A noodle, hockey stick, and spaghetti plate: a perspective on high resolution paleoclimatology. Wiley Interdisciplinary Reviews Climate Change. 1 (4): 507-516. doi: 10.1002/wcc.53
http://www.st-andrews.ac.uk/~rjsw/all%20pdfs/Franketal2010.pdf
Rob
A misunderstanding: It is not Lamb's graph of the English temperature trend (not a hockey stick!) that I claim has been become an icon.
Lamb's graph remains in good stead for me. I refer instead to the graph on p202 of FAR that is supposed to give the global trend. Perhaps not an icon. But would we agree that it has appeared over and over again on blog posts; and there it is often used as a counter to the hockey stick or as a counter to the proposition by warmists that previously (and otherwise) there was scientific agreement on a global MWP that was warmer than the 20th century? The surrounding text of FAR did not even make this claim. It described it as a local phenomenon, whereas, and in contrast, it suggested the Holocene optimum and the LIA were global. So the claim was not even made by the first assessment...except in this unreferenced and falsely labelled graph.
For those unfamiliar with the role it has played on there blogs, here are some recent appearances:
http://wattsupwiththat.com/2013/08/21/ipcc-throws-manns-hockey-stick-under-the-bus/
http://stevengoddard.wordpress.com/2013/08/12/ipcc-that-medieval-warm-period-we-used-to-believe-in-wrecks-our-story-lets-get-rid-of-it/
http://wattsupwiththat.com/2013/04/11/evidence-for-a-global-medieval-warm-period/
And some older examples:
http://wattsupwiththat.com/2010/10/22/mike-manns-secret-meeting-on-the-medieval-warm-period/
http://ecotretas.blogspot.com.au/2010/10/climategate-secret-meeting_22.html
http://wattsupwiththat.com/2010/03/10/when-the-ipcc-disappeared-the-medieval-warm-period/
http://wattsupwiththat.com/2009/11/29/the-medieval-warm-period-a-global-phenonmena-unprecedented-warming-or-unprecedented-data-manipulation/
I'm with Jiminy Cricket here: Climate Science is "an obscure backwater of science that has been given leverage far beyond its confidence and scientific techniques".
Sadly I cannot see it turning into a proper science any time soon.
On a separate note there is a transcript of yesterday's Parliamentary Debate here
BernieL - are you saying the origin is different to the speculation here?
http://climateaudit.org/2012/09/30/more-on-the-iconography-of-ipcc-1990-figure-7/
Bernie, I am not sure I would agree it has become an icon, but I take your point that the graph and the text in the FAR are contradictory. As Steve McM showed at Climate Audit, the provenance of the graph is also uncertain.
If you mean that at the time of the FAR it was not widely accepted that the MWP was global, but only regional in Europe, then it is strange how the FAR asserted that graph as meaning global.
However, since then many papers have been published showing a warm period at that time with many different proxies from many corners of the globe, suggesting the event was likley global, as was the LIA. Similarily the paper by Loehle I note above shows a MWP and an LIA, based on global proxies. These show a very close comparison to the picture in the FAR (which I understand was likely based on Lamb's diagram). So the FAR picture, although it may have misrepresented the view at the time, seems with hindsight to actually be quite a good representation of global temperatures over that period. So the question mark over the graph and its attribution in the FAR is perhaps somewhat moot?
Clivere, no. But I had forgotten about the Tinkell triptych 1986 found by Brent at CA. Thanks. The Holocene graph there is really curious. I would like to know its origin. And also for the one in FAR which remains a complete mystery. The presentation in such order of scales (usually in powers of10) I have found back to 1975. More on that in part 2. The main argument of part 1 is that there is no scientific basis to the claim that the 1000 year graph from Lamb gives the global trend. Indeed there was evidence to the contrary given by Lamb and others in 60s, 70s and 80s, and cited in FAR.
Bernie, you may be interested in the following sentence given by Lamb in a paper given at the WMO/IAMAP Symposium on Long-Term Climatic Fluctuations in 1975. The conference was held 18-23 November 1975 and I have a copy of the proceedings. I collect these things...:-)
From Lamb, H.H. (1975) Remarks on the current climatic trends and its perspective:
My bold for emphasis. Reading the above, Lamb seems to have held the view as early as 1975 that temperature trends in the north and south hemisphere were generally the same over the 1,000 year period before current, so it might follow that this opinion would lead to the graph of temperature reconstruction in Europe to be considered to be representative of the global temperature by the time we get to the FAR.
A further point to note is that in reading some of the papers in the above proceedings, it is clear to me that most authors at that time are careful not to extrapolate the implication of their results wider then geogrpahical limitation of the actual observations. So a paper referencing proxies in Germany only talks about possible interpretations of climate in Germany and not Europe for example. There was a certain preciseness about the interpretaation of results at that time.
Given the prominent role of Climate Audit in contesting proxy reconstructions, Bernie's characterization of the Lamb/IPCC 1990 diagram as being "idolized" by skeptic blogs will certainly to suggest to many readers that Climate Audit has done so - which is definitely not the case. Bernie's blog citations conspicuously did not include a single example from Climate Audit.
I've looked at the diagram mainly from an iconographic point of view. In addition to the post noted by one commenter above http://climateaudit.org/2012/09/30/more-on-the-iconography-of-ipcc-1990-figure-7/, I did a further post highly relevant to the topic, but also not cited by Bernie http://climateaudit.org/2012/10/09/the-afterlife-of-ipcc-1990-figure-7-1/. These posts provide considerable context (and references) not considered by Bernie and which, if considered, would have added texture to his account. In particular, the second post shows a number of examples where variations of the IPCC 1990 graphic were used by prominent climate scientists (including Bradley, Eddy, Crowley) to illustrate the evolution of recent temperature - including an article by Crowley in 1996 - on a scale not limited to the UK. I've also looked closely at the text of IPCC 1990 and agree that its contradictions prevent one reading too much into it. However, if one also looks at Bradley and Eddy 1991, Crowley 1996 etc, one can make a stronger attribution than Bernie has made.
Although Bernie notes that the Little Ice Age is believed to be a widespread phenomenon, Bradley and Jones contested its existence as well. One of the distinctive features of the original Mann hockey stick was the extremely low amplitude of fluctuations and its negligible LIA. My impression is that the concept of a Little Ice Age has somewhat revived in the past 10 years, since being contested in the late 1990s. The most prominent modern warming is in the Arctic, precisely the same area as the strongest medieval warming.
Steve,
Where religious practice descends into idolatry is where the representation of God (as principle or arche) is worshiped in place of God. It is for this reason that Judaism and Islam ban representations, ‘graven images.’ And this was the rationale behind various iconoclastic movements in Christianity. To talk of the popular idols of a religion is not to say that in its higher practices there is idolatry. This contrast between low and high religion is most evident in the contrast between popular and monastic practices of Buddhism and Hinduism. The analogy of idolatry is after Francis Bacon's great instauration, which became the project of the Royal Society. In the case of this graph (IPCC FAR 7.1c), it is repeatedly hoisted up on the blogs as though this image of climate history is what is being supported and defended. Whereas I proposes what should be defended are the principles of empirical science. Far from idolizing this graph, Climate Audit has exposed it for what it is. I regret not pointing this out.
Otherwise, and other than enriching the discussion, I don’t think you are making a criticism of my main arguments, but, all the same, it may help to clarify...
My contention is that IPCC FAR 7.1c misrepresents its source and misrepresents the science of the time, including that discussed in the accompanying text of FAR. I think we agree on that. Lamb never made the claim that his graph represents the global trend. Indeed, Lamb had another favorite graph that clearly showed how the pattern trended differently across a short arch of the globe running across northern Europe (I will discuss this in Part II of the essay).
Your 9Oct12 post shows how the graphs in FAR fig. 7.1 were used by prominent climate scientists in the 1990s to give/suggest/imply the global trend. Of course, this does not challenge my contention that it misrepresents the science up to 1990. Indeed, it raises an interesting point. If we consider alone the authority that such a grand UN coordinated assessment should have attained, we should expect many more citations and reproductions. Where are they? Perhaps we should be asking why this did not happen...and in contrast to how it did happen with the Hockey Stick. We have our own answers for that! And this serves to explain the noted absence of Bradley & Eddy 1991 in Bradley’s bibliography.
My headline argument remains: just because this graph quickly became an embarrassment for the IPCC -- because it gave the wrong message -- this is no reason for skeptics to fall into the trap of defending it or of using it as a defence. Again: the repeated hoisting of this idol by skeptics as though a crucifix against the demon hockey stick (& Co) only serves to oppose one form of pseudo-scientific dogma with another. I think we can agree on that also.
Yet you persist in leaving the description in your article that skeptics idolize the graph.
As evidence you post links to a few blog posts, most of which were not focused on the graph referenced, but on other aspects.
The blunt facts are; skeptics do not 'idolize' said graph nor is your representation of it as an icon accurate. It is a graph, pure and simple; one that is older and represents science and the progress of science before Manniacal and the IPCC papered over it without discussion.
Correcting your inaccurate portrayal should be your only response instead of waffling from excuses that range from idolize to icon to whatever.
Your response to Steve McIntyre is, sadly, dismissive; You ramble through a long lengthy paragraph about religion, Bacon and skeptics repeatedly hoisting the graph up on blogs, yet the only correct words are,
, yet even here you add in six words that focus on you supposedly pointing Steve McIntyre's role out. You didn't, you are forced to own up to it afterwards.If blogs have repeatedly hoisted the 'IPCC FAR 7.1c' up on their websites, perhaps you can prove your claim? Exactly how many times did blogs actually hoist up the 'IPCC FAR 7.1c' for adoration, worship, icons? Give the preponderance of blog postings, repeatedly requires more than a few times.
Thinking Scientist,
Nice keep! And you know Lamb was born 100 years from the coming Autumn equinox. CRU celebrated with a conference last weekend..with no mention as far as I could see of his persistent skepticism.
Sometimes both positions are right and the truth slips in between. Lamb studied oscillations and waves on various temporal and spacial scales, and not just the north Atlantic oscillation. Imagine a cold front moving across a continent, or a heat wave. Or the movement of a warm sea surface anomaly from the equator after an El Nino (and perhaps continuing during a La Nina). Now imagine such patterns moving and transforming on a centennial scale. This is how one might imagine many regions experiencing periods warmer periods in succession with minimal impact on the global mean. And they could still be more or less in parallel. We know all of this. But we sometimes forget this in this debate. We get caught up in the obsession with GMT, which was a product of late 20th century global climate anxiety, and which demanded an answer this question: In the past, when was the whole atmosphere collectively slightly warmer/cooler on average at the same time?
This question could be addressed on the geological scale. But on the millennium scale?? In the 70s and 80s there were many papers on the table proposing regional trends from proxies back through the Holocene. Many (most?) of them showed warmer times in the past. But just like weather trends, the climate trends in different regions varied across time. Instead of trying to go for a global average at one time, climatologists were working just like meteorologists but on a different time scale. They used data from particular points on the globe to find patterns of climate change across the surface of the globe. And this is how the theory of the various oscillation emerged. We know all of this. But the point is that there was barely any interest in trying to answer the question of a global average trend. That is, except in response to the demand due to the global cooling/warming anxiety that began in the 1970s.
I am not sure I am right about this, but it does seem that, in the 1970s, if asked, no reasonable scientist would suggest that they had enough evidence to propose that they could give a value for the average global temperature for the 12 century AD. However, the various assessment reports responding to cooling/warming alarm were driven to suggest that this is possible. This is where the problem might lie. In the 1970s and 1980s the science and the scientists were not ready for this demand. So this is why, at first, regional charts from Lamb (first my fig 5 then my fig 1) came to stand in for the global average . That is, until a schools of paleoclimatology emerged in response to this demand, i.e., until the Hockey team in the late 1990s came to deliver on the previously much maligned tree ring data.
Dr Tim ball article from 24th July 2011 on the IPCC Hockey stick.
http://drtimball.com/2011/scientific-casualties-of-the-ipcc-hockey-stick-fiasco/
He thinks Bristlecone pine growth is primarily controlled by precipitation.
I wonder if the Hockey stick graph tells us that increasing the level of CO2 in the atmosphere will increase the rate of tree growth, if so, will carpenters be able to make more hockey sticks, sooner, faster ? Or maybe more broom sticks for those who prophecy doom.
Maybe the IPCC just had the graph upside down. It might turn out to make a better fit with temperature if the head represented the increase during the 80s & 90s and the handle represented the 21st century. Well , unlike the IPCC, I am not a fortune teller, so I don't know what the climate will be in 2100. Like the value of shares, going on past performance, average global temperatures can go down as well as up
Rob Wilson, thanks for the reference to Frank et al 2010. This in turn refers to Groveman et al (Geophys Res Lett 1979, 6:767–769) and Jacoby & D’Arrigo (Clim Change 1989, 14:39–59) which give northern hemisphere reconstructions back as far as Manley. Neither are cited in FAR Ch7.